Methods and devices for installing standard and reverse shoulder implants

ABSTRACT

Surgical procedures, tools and implants are disclosed for both conventional and reverse shoulder implant surgeries. The improved procedures, tools and implants relate to humeral head resurfacing, humeral head resection for standard implants, humeral head resection for reverse shoulder implants, glenoid resurfacing for standard shoulder implants and glenoid resurfacing for reverse shoulder implants. 3D scans and x-rays are used to develop virtual models of the patient anatomy, identify patient specific landmarks for anchoring guide wire installation blocks, templates and drill guides. 3D scans are also used to design patient specific tools and implants for the shoulder implant procedures and to pre-operatively determine the appropriate inclination and retroversion angles.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. patent application Ser. No.16/568,879, filed Sep. 12, 2019 entitled “METHODS AND DEVICES FORINSTALLING STANDARD AND REVERSE SHOULDER IMPLANTS,” which claims thepriority benefit of U.S. patent application Ser. No. 14/993,517, filedJan. 12, 2016 entitled “METHODS AND DEVICES FOR INSTALLING STANDARD ANDREVERSE SHOULDER IMPLANTS,” which claims the priority benefit of U.S.patent application Ser. No. 13/814,124, filed Jun. 4, 2013 entitled“METHODS AND DEVICES FOR INSTALLING STANDARD AND REVERSE SHOULDERIMPLANTS,” which is a U.S. national stage filing under 35 U.S.C. § 371of International Application No. PCT/US2011/043719 filed Jul. 12, 2011entitled “METHODS AND DEVICES FOR INSTALLING STANDARD AND REVERSESHOULDER IMPLANTS”, which claims the priority benefit of U.S.Provisional Patent Application Ser. No. 61/373,092, filed on Aug. 12,2010, entitled “METHODS AND DEVICES FOR INSTALLING STANDARD AND REVERSESHOULDER IMPLANTS,” each of which is incorporated herein by reference.

DESCRIPTION Technical Field

This disclosure relates generally to joint implants and moreparticularly to systems and methods for facilitating installations ofvarious forms of shoulder implants that are specific to the anatomy ofthe patient.

Background

When a joint, such as a shoulder, hip or knee, becomes impaired due toarthritis, disease or trauma, it is sometimes necessary to replace allor part of the joint with one or more prostheses to restore function.Four anatomical characteristics that relate to shoulders are humeral andglenoid inclination and humeral retroversion and glenoid version, all ofwhich can change as disease in the shoulder joint progresses.

For purposes of this disclosure, humeral inclination is defined as theangle between the plane of the anatomical neck of the proximal humerusand the metaphyseal axis of the humerus. Glenoid inclination is definedin the coronal plane as the angle between a line identifying theinferior-superior axis of the glenoid and a line connecting theintersection of the scapular spine with the medial border of the scapulaand the middle of the spinoglenoid notch. Further, humeral retroversion(or humeral torsion) is defined as the angle between the normal vectorto a plane defined by the perimeter of the anatomical neck and thetransepicondylar axis of the distal humerus. Finally, glenoid version isdefined in the axillary view as the angle between a line identifying theanterior-posterior rim of the glenoid cavity and a line perpendicular toa line identifying the scapular blade. Correction and modification ofboth humeral and glenoid inclination and version changes in diseasedshoulder joints are benefits of successful shoulder implant procedures.

Anatomically, the average humeral inclination is approximately 135°, butcan range from about 120° to about 150°. Average humeral retroversion isapproximately 30°, but can range from about −5° to about 60°. Glenoidinclination can range from about 80° to about 100°, whereas glenoidversion can range from about 0° to about −14°. In order to optimizebalancing of soft tissues and post-operative function, it is crucial toestablish the proper inclination and version for each patient. Incorrectinclination and version can lead to problems including limited function,subsequent dislocations, and prosthetic component loosening and wear.Unfortunately, with existing implants and installation techniques, thesecritical parameters are chosen in a freehand manner.

In many cases, when an implant is used as treatment for an arthriticshoulder joint, it is necessary to remove or resect the diseased humeralhead and prepare the proximal end of the humeral shaft to receive thestem, body, inclination set and head. It is important that the humeralhead preparation be accurate so that the position of the implant, whichis determined in part by the configuration of the humeral head,replicates the original anatomic position of the humeral head.

In less severe cases, the humeral head may be resurfaced by installingan implant that covers the humeral head after the humeral head has beenresurfaced which removes abnormalities such as osteophytes,tuberositites, etc. In more severe cases, such as irreparable rotatorcuff rupture, standard shoulder implants, as described above, would notprovide sufficient pain-free joint stability or an adequate range ofmotion. Thus, an implant with a “reverse” joint has been developed wherea base plate is attached to the glenoid fossa with screws after theglenoid fossa has been resurfaced. A head, sometimes referred to as aglenosphere, is attached to the glenoid base plate, as opposed to thehumeral head. The humeral head is still resected and a stem is inserteddownward into the intramedullary canal. A cup-shaped reverse body isattached to the proximal end of the stem, which receives a polymericinsert, receives the head or glenosphere that is fixed to the glenoidbase plate.

The above procedures, while providing significant advancements, stillsuffer from certain drawbacks. For example, the most critical step in ahumeral head resurfacing technique is placement of the initial guidewire, over which the humeral head resurfacing body slides.Unfortunately, the placement of the guidewire is performed using afreehand technique and an alignment tool. Contemporaneously, the surgeonestimates the desired inclination from the coronal (vertical) plane ortransverse (horizontal) plane and maintains this desired inclinationwhile the surgeon estimates a desired retroversion. Holding the headtemplate in this exact position, the surgeon then drive drives thecentral guide wire or K-wire through the guide of the template using adrill or other suitable tool.

Thus, an optimal final positioning of the symmetrical implant on theasymmetrical humeral head is dependent on the surgeon's ability tovisualize the desired orientation in three dimensions and the surgeon'sability to hold the head template steady while inserting the guide wire.

For traditional (non-reverse) shoulder implants, many surgeons useintramedullary cutting jigs or a freehand technique to resect thehumeral head. For the more severe cases that require a reverse implantas described above, an intramedullary cutting jig is required tominimize the possibility of reaming with the incorrect retroversion,which could cause the screws that anchor the glenoid base plate toextend through or “break out” of the cortical bone structure of theglenohumeral joint or scapula. To avoid this problem, a complexintramedullary cutting jig is used

SUMMARY OF THE DISCLOSURE

It would therefore be advantageous to replace as many freehand steps aspossible with precise pre-determined and pre-fabricated templates andimplants designed pre-operatively. It would also be advantageous todetermine the desired retroversion and inclination pre-operatively.

Methods of resurfacing a humeral head and fabricating a humeral headtemplate are disclosed that comprise obtaining a 3D scan of the humeralhead. The 3D scan may be an MRI, a CT (CAT) scan or other suitable typeof 3D scan, depending upon patient conditions and surgeon preference.From the 3D scan, patient specific anatomy is identified on the humeralhead for purposes of stabilizing a humeral head template. A desiredinclination and retroversion are also determined or identified basedupon the one or more of the extent of patient's disease, the patient'sanatomy and one or more determinations made by the surgeon as to theinclination and retroversion that can be achieved. A humeral headtemplate is then fabricated based upon the 3D scan of the humeral headand the identified patient specific anatomy is used for stabilizing thehumeral head template. A guide or boss is formed separately or as anintegral part of the humeral head template for receiving a guide wire atthe desired inclination and retroversion. To resurface the humeral head,the humeral head template is mounted on the humeral head with the guideand the guide wire is inserted through the guide and into the humeralhead. The template is then removed over the guide wire and a humeralhead implant is mounted over the guide wire and onto the humeral headwhere it is fixed using known procedures.

In an embodiment, patient specific anatomy for stabilizing a humeralhead template may be selected from the group consisting of but notlimited to: an articular surface; a diseased area on the articularsurface; a bicipital groove; a greater tubercle; a lesser tubercle; afootprint of the greater tubercle; a metaphyseal axis; an anatomicalneck; an anterior humeral head; a posterior humeral head; an anteriorsurgical neck; a posterior surgical neck; one or more soft tissuestructure; and combinations thereof.

In another refinement, the determination of the inclination comprisesdetermining a plane of the anatomical neck of the humeral head from the3D scan, determining a metaphyseal axis from the 3D scan and determininga desired inclination from the angle between the plane of the anatomicalneck and the metaphyseal axis.

In another refinement, the method the determining of at least one of theinclination and retroversion and further comprises determining a centerpoint of the head of the humerus, determining a plane of an anatomicalneck of the humerus from the three-dimensional scan; determining a linethrough the point and normal to the plane.

In another refinement, the determining of the inclination furthercomprises determining a center point of the head of the humerus,determining a plane of an anatomical neck from the three-dimensionalscan, determining a line through the point and normal to the plane,determining a metaphyseal axis from the three-dimensional scan, anddetermining a desired inclination from the angle between the line andthe metaphyseal axis.

In another refinement, the determining of the retroversion comprisesdetermining a center point of the head of the humerus, determining aplane of an anatomical neck of the humerus from the three-dimensionalscan, determining a line through the point and normal to the plane,acquiring an image of the humerus, determining the distaltrans-epicondylar axis from the image, and determining a desiredretroversion from the angle between the line and the distaltrans-epicondylar axis.

A method for fabricating a cutting block for resecting a humeral head isalso disclosed. The method comprises obtaining a three-dimensional scanof a proximal humerus, identifying patient specific anatomy on theproximal humerus, and fabricating a cutting block based upon thethree-dimensional scan of the proximal humerus, and the identifiedpatient specific anatomy.

In an embodiment, the fabricating of the cutting block further comprisesdetermining a center point of the head of the humerus, determining aplane of an anatomical neck of the humerus from the three-dimensionalscan, and determining a line through the point and normal to the plane.

In another refinement, the fabricating of the cutting block comprisesdetermining the inclination. The method further comprises determining acenter point of the head of the humerus, determining a plane of ananatomical neck from the three-dimensional scan, determining a linethrough the point and normal to the plane, determining a metaphysealaxis from the three-dimensional scan, and determining a desiredinclination from the angle between the line and the metaphyseal axis.

In another refinement, the fabricating of the cutting block comprisesdetermining the retroversion. The fabrication comprises determining acenter point of the head of the humerus, determining a plane of ananatomical neck of the humerus from the three-dimensional scan,determining a line through the point and normal to the plane, acquiringan image of the humerus, determining the distal trans-epicondylar axisfrom the image, and determining a desired retroversion from the anglebetween the line and the distal trans-epicondylar axis.

In another refinement, the determination of the desired retroversioncomprises determining a plane of the anatomical neck of the humeral headfrom the 3D scan. A superior-inferior x-ray of the humeral head andelbow that exposes the distal epicondylar axis from the x-ray is takento provide an estimation of the existing retroversion and a desiredretroversion is determined from an axis of the humerus.

In another refinement, a superior-inferior x-ray of the humeral head anddistal epicondylar axis are taken and used with three-dimensional scanto determine the desired retroversion.

In an embodiment, the determining of the retroversion comprisesdetermining a center point of the head of the humerus, determining aplane of an anatomical neck of the humerus from the three-dimensionalscan, determining a line through the point and normal to the plane,acquiring an image of the humerus, determining the distaltrans-epicondylar axis from the image, and determining a desiredretroversion from the angle between the line and the distaltrans-epicondylar axis.

In an embodiment, the humeral head template may be mounted and fixed tothe humeral head without reaming the humeral head. In anotherrefinement, the humeral head is reamed to provide a spherical surfacefor receiving a humeral head implant.

In an embodiment, a marker is used transversely across the patient'selbow that marks the distal epicondylar axis, which is used with thesuperior-inferior x-ray to determine the existing retroversion and thedesired retroversion angle of the implant.

In an embodiment, the humeral head implant is fabricated with aspherical outer surface based upon the 3D scan of the humeral head andthe identified patient specific anatomy for stabilizing the humeral headtemplate at the desired inclination and retroversion.

In another refinement, an axis of the guide wire and/or guide forreceiving the guide wire are adjusted based upon one or more conditionsof the glenoid fossa.

Methods for resecting humeral heads and for fabricating patient specificcutting blocks for humeral head resections are also disclosed. Onedisclosed method comprises obtaining a 3D scan of a humeral head.Patient specific anatomy is identified on the humeral head, proximallyof the anatomical neck or distally of the humeral head and anatomicalneck for stabilizing a cutting block on the humeral head. A cuttingblock is fabricated based upon the 3D scan of the humeral head, whichmay also include portions of the humerus distal to the humeral head,such as the metaphyseal cylinder or flute, and negative geometry of theidentified patient specific anatomy is used in fabricating the cuttingblock for purposes of stabilizing the cutting block on the humeral head.The cutting block is then attached to the humeral head. The cuttingblock presents a resection plane and resection of the humeral head isaccomplished using the cutting block as a guide.

In an embodiment, patient specific anatomy for fabricating a patientspecific cutting block and stabilizing a cutting block on a humeral headmay selected from the group consisting of but not limited to: ananterior portion of the proximal humerus; a superior portion of theproximal humerus; an inferior portion of the proximal humerus; atuberositite; an osteophyte; a biceps groove; a soft tissue insertionpoint; and combinations thereof.

In an embodiment, the cutting block is attached to the humeral head or aproximal portion of the humerus using one or more fasteners selectedfrom the group consisting of bone spikes, trocar pins, speed pins, bonescrews and combinations thereof.

In an embodiment, the cutting block may attached to the proximal humeralhead, the distal humeral head, a portion of the humeral head distally ofthe anatomical neck of the humeral head or a portion of the metaphysealshaft. Other patient specific locations for attaching the cutting blockwill be apparent to those skilled in the art and the disclosed methodsare not limited to the locations recited here.

Methods for resecting humeral heads and fabricating cutting blocks arealso disclosed that are designed for reverse shoulder implantprocedures. The methods include obtaining a 3D scan of the humeral headand identifying an anatomical neck of the humeral head in a vectornormal to the anatomical neck. The distal epicondylar axis is identifiedusing a superior-inferior x-ray of the humeral head and the elbow thathas been marked with a marker that extends transversely across the elbowalong the epicondylar axis. A resection plane is selected through thehumeral head at an angle of about 65° from the epicondylar axis (or aresection plane of about 155° from the horizontal or coronal plane). Acutting block is fabricated based upon the 3D scan and the negativegeometry of the identified patient specific anatomy for stabilizing thecutting block at the desired resection plane. The cutting block is thenattached to the humeral head at the desired resection plane. Resectionis carried out using the cutting block as a guide.

In an embodiment, the patient specific anatomy for cutting blocks forreverse shoulder implants is selected from the group consisting of butnot limited to: an anterior portion of the proximal humerus; a superiorportion of the proximal humerus; an inferior portion of the proximalhumerus; a tuberositite; an osteophyte; a biceps groove; a soft tissueinsertion point; and combinations thereof.

In an embodiment, the cutting block may be attached to the humeral headusing one or more fastening elements as described above. In anembodiment, the cutting block is attached to the proximal humeral head,distal humeral head, and a portion of the humeral head distal to theanatomical neck or the metaphyseal shaft. Other patient specificlocations for attaching the cutting block will be apparent to thoseskilled in the art and the disclosed methods are not limited to thelocations recited here.

In an embodiment, a jig or apparatus is also disclosed for performingthe 3D scan and superior-inferior axial x-ray of the humerus whilemaintaining proper position of the patient's arm and shoulder. A firstplate with a first holder is used to hold the patient's arm in placebetween the patient's elbow and the humeral head. A second plateperpendicular to the first plate and including a second holder forholding the patient's elbow is also provided and further includes atleast one additional holder for holding at least a portion of thepatient's hand or wrist in place during the procedure.

Methods for fabricating glenoid templates for inserting a guide wire ata desired trajectory during a resurfacing of a glenoid fossa are alsodisclosed. One method comprises: obtaining a three-dimensional scan of ascapula; identifying patient specific anatomy on the scapula;determining a plane of the glenoid fossa; fabricating the glenoidtemplate based upon the three-dimensional scan of the scapula, theidentified patient specific anatomy; and forming a guide on the glenoidtemplate for receiving a guide wire at a desired location, inclinationand version.

In an embodiment, the determining of at least one of the location,inclination and version comprises determining a desired center point onthe glenoid fossa, determining a plane of a glenoid of the scapula fromthe three-dimensional scan, and determining a line through the point andnormal to the plane.

In another refinement, the determining of at least one of the desiredlocation, inclination and version further comprises determining anoptimal placement of an implant assembly on the three-dimensional scan.

In an embodiment, the determining of the inclination comprises:determining a first point at the intersection of the scapula spine andthe medial border of the scapula; determining a second point at themiddle of the spinoglenoid notch; determining a first line through thefirst and second points; determining a third point at the superiormargin of the glenoid fossa; determining a forth point at the inferiormargin of the glenoid fossa; determining a second line through the thirdand fourth points; and determining a desired inclination from an anglebetween the first and second lines.

In an embodiment, the determining of the version comprises determining afirst point at the anterior margin of the glenoid fossa, determining asecond point at the posterior margin of the glenoid fossa, determining afirst line through the first and second points, determining a thirdpoint at the midpoint of the glenoid fossa, determining a forth point atthe vertebral border of the scapula, determining a second line throughthe third and fourth points; determining a third line which isperpendicular to the second line; and determining a desired version froman angle between the first and third lines.

In an embodiment, the axis of the guide wire may be adjusted based onone or more conditions of a humeral head or soft tissue structure.

Methods for resurfacing glenoid fossas, methods for fabricating patientspecific blocks referred to as glenoid blocks for inserting guide wiresinto glenoid fossas and glenoid fossa drill guides are also disclosed.The surgical techniques for preparing the glenoid fossa for a reverseshoulder implant and for a standard shoulder implant are different. Fora standard implant, one disclosed method includes obtaining a 3D scan ofthe glenoid fossa and identifying patient specific anatomy on theglenoid fossa for purposes of stabilizing a glenoid block that is usedfor inserting a guide wire into the center of the glenoid fossa. Adetermination of an original plane of the glenoid fossa prior to theonset of disease is also made. The guide wire may be inserted at anintersection of the superior-interior and anterior-posterior axis forstandard implants. A patient specific glenoid block is fabricated fromthe 3D scan.

In an embodiment, a method of resurfacing a glenoid fossa comprisesobtaining a three-dimensional scan of a scapula. Patient specificanatomy on the scapula is identified. A desired location, inclinationand version are identified. Fabricating a template based upon thethree-dimensional scan of the scapula, the identified patient specificanatomy and forming a guide on the template for receiving a guide wireat the desired location, inclination and version. Then, the template ismounted onto the scapula, inserting the guide wire through the guide andinto the glenoid fossa, removing the template, inserting at least oneinstrument over the guide wire to prepare the glenoid for receiving animplant, removing the instrument and the guide wire; and mounting theglenoid implant to the glenoid fossa.

In an embodiment, the determining of at least one of the inclination andversion further comprises determining a desired center point on theglenoid fossa, determining a plane of a glenoid of the scapula from thethree-dimensional scan, and determining a line through the point andnormal to the plane.

In another refinement, the determining of the inclination comprisesdetermining a first point at the intersection of the scapula spine andthe medial border of the scapula, determining a second point at themiddle of the spinoglenoid notch, determining a first line through thefirst and second points, determining a third point at the superiormargin of the glenoid fossa, determining a forth point at the inferiormargin of the glenoid fossa, determining a second line through the thirdand fourth points, and determining a desired inclination from an anglebetween the first and second lines.

In another refinement, the determining of the version comprisesdetermining a first point at the anterior margin of the glenoid fossa,determining a second point at the posterior margin of the glenoid fossa,determining a first line through the first and second points,determining a third point at the midpoint of the glenoid fossa,determining a forth point at the vertebral border of the scapula,determining a second line through the third and fourth points,determining a third line which is perpendicular to the second line, anddetermining a desired version from an angle between the first and thirdlines.

In another refinement, the glenoid fossa is reamed prior to mounting theglenoid template onto the glenoid fossa.

For reverse implants, the guide wire may be inserted slightlyposteriorly and inferiorly to the intersection and the glenoid block isfabricated with this concept in consideration. Further, the surgeon maydesire to insert the guide wire into the glenoid fossa along an axisthat ranges from 0° to 10° inferiorly from the plane of the originalpre-diseased glenoid fossa. Again, the glenoid block and guide wireguide can be fabricated with these concepts in consideration. Theappropriately fabricated glenoid block is mounted on to the glenoidfossa and the guide wire is inserted through the guide of the glenoidblock at the desired angle before the glenoid block and guide areremoved. A central hole is drilled into the glenoid fossa for purposesof receiving the central peg of the glenoid base plate. A cannulateddrill is used to drill the central hole over the guide wire.

A drill guide may mounted in the center hole and positioned by thesurgeon before peripheral holes are drilled through the drill guide forreceiving the locking screws. The glenoid base plate may be fixed to theglenoid fossa with fasteners that extend through the peripheral holes.

The patient specific anatomy for supporting the glenoid block in placeduring the guide wire insertion procedure for both standard and reverseimplants may be selected from the group consisting of, but not limitedto: an anterior face of the glenoid, a posterior face of the glenoid, amedial face of the glenoid, a portion of the scapular neck, a medialhard stop on the glenoid face, a posterior face of the glenoid, ajunction of a coracoid and the glenoid face, and combinations thereof.

In an embodiment, the glenoid fossa is reamed after the drilling of thecentral hole for the central peg of the glenoid base plate or glenoidimplant and prior to the mounting of the drill guide on the glenoidfossa.

One disclosed method for reverse implant procedures includes obtaining a3D scan of the glenoid fossa and identifying patient specific anatomy onthe glenoid fossa for purposes of stabilizing the glenoid block. Adetermination of an original plane of the glenoid fossa prior to theonset of disease is also made. Instead of inserting the guide wirethrough an intersection of the superior-interior and anterior-posterioraxis, the guide wire is inserted slightly posteriorly and inferiorly tothis intersection and the glenoid block is made with this concept inconsideration. Further, the surgeon may desire the guide wire to beinserted into the glenoid fossa along an axis that ranges from 0° to 10°from the plane of the original pre-diseased glenoid fossa. Again, theglenoid block and guide wire guide can be made with these concepts inconsideration. The appropriately fabricated glenoid block is mounted onto the glenoid fossa and the guide wire is inserted through the guide ofthe glenoid block at the desired angle before the glenoid block andguide are removed. A central hole is drilled into the glenoid fossa forpurposes of receiving the central peg of a glenoid base plate, which isheld in place by locking screws as opposed to a glenoid implant, whichmay be cemented in place. A cannulated drill is used to drill thecentral hole over the guide wire. A drill guide is mounted in the centerhole and positioned by the surgeon before peripheral holes are drilledthrough the drill guide for receiving the locking screws. The glenoidbase plate is then fixed to the glenoid fossa with fasteners that extendthrough the peripheral holes.

In an embodiment, the glenoid fossa is reamed after the drilling of thecentral hole for the central peg and prior to the mounting of the drillguide on the glenoid fossa.

Another more specialized procedure for a reverse shoulder implant isalso disclosed along with a two-piece bone screw drill guide. Thisprocedure and the two-piece bone screw drill guide are intended tofurther reduce the possibility of breakout or an extension of thelocking screws through the scapular cortical bone. Such a procedureincludes using a two-piece bone screw drill guide that includes aninferior bone screw drill guide and a superior bone screw drill guidethat are coupled together in a manner so to provide some lateralmovement of the superior bone screw drill guide with respect to theglenoid fossa during the drilling process.

Patient specific anatomy on an inferior portion of the glenoid fossa isidentified for purposes of stabilizing the inferior bone screw drillguide at the inferior end of the glenoid fossa. The superior bone screwdrill guide is also fabricated based upon the 3D scan that can beremovably coupled to the inferior bone screw drill guide to form thetwo-piece bone screw drill guide. Peripheral holes for accommodatinglocking screws are then drilled through the superior bone screw drillguide. The superior bone screw drill guide is then removed from theinferior bone screw drill guide. A glenoid base plate is then fixed tothe glenoid fossa with fasteners that extend through the peripheralholes and the central peg of the glenoid base plate is received in thecentral hole drilled with the cannulated drill as described above.

In another refinement, the glenoid fossa is reamed after removal of theglenoid block before or after the drilling of the central hole over theguide wire.

In another refinement, the patient specific anatomy for stabilizing theinferior bone screw drill guide is selected from the group consistingof, but not limited to: an intraglenoid tubercule; a scapular pillar;one or more portions of the glenoid face; and combinations thereof.

In another refinement, a two-piece drill guide is used to drill theperipheral holes for the peripheral pegs of a glenoid implant that iscemented to the glenoid fossa during a standard implant procedure. Thetwo-piece drill guide for the standard implant procedure includes aninferior drill guide slidably coupled to a superior drill guide. Theinferior drill guide is fabricated based on the 3D scan an is stabilizedat the inferior end of the glenoid fossa using patient specific anatomyselected from the group consisting of, but not limited to: anintraglenoid tubercule; a scapular pillar; one or more portions of theglenoid face; and combinations thereof.

There is provided a method of fabricating a template used in a humeralhead resurfacing procedure, the method comprising: obtaining athree-dimensional scan of a proximal humerus; identifying patientspecific anatomy on the proximal humerus; determining a desiredlocation, inclination and retroversion; fabricating the template basedupon the three-dimensional scan of the proximal humerus, the identifiedpatient specific anatomy; and forming a guide on the template forreceiving a guide wire at the desired location, inclination andretroversion.

In some embodiments, the patient specific anatomy is selected from thegroup consisting of an articular surface, a diseased area on thearticular surface, a bicipital groove, a greater tubercle, a lessertubercle, a footprint of the greater tubercle, a metaphyseal axis, atrans-epicondylar axis, an anatomical neck, an anterior portion of theproximal humerus, a posterior portion of the proximal humerus, anosteophite, one or more soft tissue structures and combinations thereof.

In some embodiments, the step of determining of at least one of theinclination and retroversion further comprises: determining a centerpoint of the head of the humerus; determining a plane of an anatomicalneck of the humerus from the three-dimensional scan; and determining aline through the point and normal to the plane.

In some embodiments, the step of determining of the inclinationcomprises: determining a center point of the head of the humerus;determining a plane of an anatomical neck of the humerus from thethree-dimensional scan; determining a line through the point and normalto the plane; determining a metaphyseal axis from the three-dimensionalscan; and determining a desired inclination from an angle between theline and the metaphyseal axis.

In some embodiments, the step of determining of the retroversioncomprises: determining a center point of the head of the humerus;determining a plane of an anatomical neck of the humerus from thethree-dimensional scan; determining a line through the point and normalto the plane; acquiring an image of the humerus; determining a distaltrans-epicondylar axis from the image; and determining a desiredretroversion from an angle between the line and the distaltrans-epicondylar axis.

In some embodiments, the method further comprises taking asuperior-inferior x-ray of the humeral head and distal trans-epicondylaraxis and using the x-ray and the three-dimensional scan to determine adesired retroversion.

In some embodiments, the method further comprises adjusting an axis ofthe guide wire based on one or more conditions of a glenoid fossa.

There is provided a method of resurfacing a humeral head, the methodcomprising: obtaining a three-dimensional scan of a humerus; identifyingpatient specific anatomy on the humerus; determining a desired location,inclination and retroversion; fabricating a template based upon thethree-dimensional scan of the humerus and the identified patientspecific anatomy; forming a guide on the template for receiving a guidewire at the desired location, inclination and retroversion; mounting thetemplate onto the humeral head; inserting the guide wire through theguide and into the humeral head; removing the template; inserting aninstrument over the guide wire to prepare the head for receiving animplant; removing the instrument and the guide wire; and mounting theimplant to the humeral head.

In some embodiments, the patient specific anatomy is selected from thegroup consisting of an articular surface, a diseased area on thearticular surface, a bicipital groove, a greater tubercle, a lessertubercle, a footprint of the greater tubercle, a metaphyseal axis, atrans-epicondylar axis, an anatomical neck, an anterior portion of theproximal humerus, a posterior portion of the proximal humerus, anosteophite, one or more soft tissue structures and combinations thereof.

In some embodiments, the method further comprises the step ofdetermining of at least one of the inclination and retroversion furthercomprises: determining a center point of the head of the humerus;determining a plane of an anatomical neck of the humerus from thethree-dimensional scan; and determining a line through the point andnormal to the plane.

In some embodiments, the step of determining of the inclinationcomprises: determining a center point of the head of the humerus;determining a plane of an anatomical neck from the three-dimensionalscan; determining a line through the point and normal to the plane;determining a metaphyseal axis from the three-dimensional scan; anddetermining a desired inclination from an angle between the line and themetaphyseal axis.

In some embodiments, the step of determining of the retroversioncomprises: determining a center point of the head of the humerus;determining a plane of an anatomical neck of the humerus from thethree-dimensional scan; determining a line through the point and normalto the plane; acquiring an image of the humerus; determining a distaltrans-epicondylar axis from the image; and determining a desiredretroversion from an angle between the line and the distaltrans-epicondylar axis.

In some embodiments, the method further comprises taking asuperior-inferior x-ray of the humeral head and distal trans-epicondylaraxis and using the x-ray and the three-dimensional scan to determine adesired retroversion.

In some embodiments, the method further comprises adjusting an axis ofthe guide wire based on one or more conditions of a glenoid fossa.

There is provided a method for fabricating a cutting block for resectinga humeral head, the method comprising: obtaining a three-dimensionalscan of a proximal humerus; identifying patient specific anatomy on theproximal humerus; and fabricating the cutting block based upon thethree-dimensional scan of the proximal humerus, and the identifiedpatient specific anatomy.

In some embodiments, the patient specific anatomy is selected from thegroup consisting of an articular surface, a diseased area on thearticular surface, a bicipital groove, a greater tubercle, a lessertubercle, a footprint of the greater tubercle, a metaphyseal axis, atrans-epicondylar axis, an anatomical neck, an anterior portion of theproximal humerus, a posterior portion of the proximal humerus, anosteophite, one or more soft tissue structures and combinations thereof.

In some embodiments, the step of fabricating the cutting blockcomprises: determining a center point of the head of the humerus;determining a plane of the anatomical neck of the humerus from thethree-dimensional scan; and determining a line through the point andnormal to the plane.

In some embodiments, the step of determining the inclination comprises:determining a center point of the head of the humerus; determining aplane of the anatomical neck from the three-dimensional scan;determining a line through the point and normal to the plane;determining a metaphyseal axis from the three-dimensional scan; anddetermining a desired inclination from an angle between the line and themetaphyseal axis.

In some embodiments, the step of determining the retroversion comprises:determining a center point of the head of the humerus; determining aplane of the anatomical neck of the humerus from the three-dimensionalscan; determining a line through the point and normal to the plane;acquiring an image of the humerus; determining a distaltrans-epicondylar axis from the image; and determining a desiredretroversion from an angle between the line and the distaltrans-epicondylar axis.

There is provided a method for resecting a humeral head, the methodcomprising: obtaining a three-dimensional scan of a proximal humerus;identifying patient specific anatomy on the proximal humerus;fabricating a cutting block based upon the three-dimensional scan of theproximal humerus, and the identified patient specific anatomy; attachingthe cutting block to the proximal humerus; and resecting the humeralhead using the cutting block as a guide.

In some embodiments, the patient specific anatomy is selected from thegroup consisting of an articular surface, a diseased area on thearticular surface, a bicipital groove, a greater tubercle, a lessertubercle, a footprint of the greater tubercle, a metaphyseal axis, atrans-epicondylar axis, an anatomical neck, an anterior portion of theproximal humerus, a posterior portion of the proximal humerus, anosteophite, one or more soft tissue structures and combinations thereof.

In some embodiments, the cutting block is attached to the humeral headusing one or more fasteners selected from the group consisting of bonespikes, trocar pins, speed pins, bone screws and combinations thereof.

In some embodiments, the step of fabricating the cutting block comprisesdetermining a center point of the head of the humerus; determining aplane of an anatomical neck of the humerus from the three-dimensionalscan; and determining a line through the point and normal to the plane.

In some embodiments, the step of determining the inclination comprises:determining a center point of the head of the humerus; determining aplane of an anatomical neck from the three-dimensional scan; determininga line through the point and normal to the plane; determining ametaphyseal axis from the three-dimensional scan; and determining adesired inclination from an angle between the line and the metaphysealaxis.

In some embodiments, the step of determining the retroversion comprises:determining a center point of the head of a humerus; determining a planeof an anatomical neck of the humerus from the three-dimensional scan;determining a line through the point and normal to the plane; acquiringan image of the humerus; determining a distal trans-epicondylar axisfrom the image; and determining a desired retroversion from an anglebetween the line and the distal trans-epicondylar axis.

There is provided a method for fabricating a glenoid template forinserting a guide wire at a desired trajectory during a resurfacing of aglenoid fossa, the method comprising: obtaining a three-dimensional scanof a scapula; identifying patient specific anatomy on the scapula;determining a plane of the glenoid fossa; fabricating the glenoidtemplate based upon the three-dimensional scan of the scapula, theidentified patient specific anatomy; and forming a guide on the glenoidtemplate for receiving a guide wire at a desired location, inclinationand version.

In some embodiments, the first piece of the guide is fabricated based onpatient specific anatomy selected from the group consisting of a face ofthe glenoid fossa, a diseased area on a face of the glenoid fossa, ananterior rim of glenoid, a posterior rim of glenoid, an inferior rim ofglenoid, a superior rim of glenoid, an infraglenoid tubercle, asupraglenoid tubercle, a scapula neck, a scapula blade, a coracoidspine, a scapula spine, a midpoint of the glenoid fossa, one or moresoft tissue structures, and combinations thereof.

In some embodiments, the step of determining of at least one of thelocation, inclination and version comprises determining a desired centerpoint on the glenoid fossa; determining a plane of a glenoid of thescapula from the three-dimensional scan; determining a line through thepoint and normal to the plane.

In some embodiments, the step of determining of at least one of thedesired location, inclination and version further comprises: determiningan optimal placement of an implant assembly on the three-dimensionalscan.

In some embodiments, the step of determining of the inclinationcomprises: determining a first point at the intersection of the scapulaspine and the medial border of the scapula; determining a second pointat the middle of the spinoglenoid notch; determining a first linethrough the first and second points; determining a third point at thesuperior margin of the glenoid fossa; determining a forth point at theinferior margin of the glenoid fossa; determining a second line throughthe third and fourth points; determining a desired inclination from anangle between the first and second lines.

In some embodiments, the method further includes the step of determiningversion comprising: determining a first point at an anterior margin ofthe glenoid fossa; determining a second point at the posterior margin ofthe glenoid fossa; determining a first line through the first and secondpoints; determining a third point at the midpoint of the glenoid fossa;determining a forth point at the vertebral border of the scapula;determining a second line through the third and fourth points;determining a third line, which is perpendicular to the second line; anddetermining a desired version from an angle between the first and thirdlines.

In some embodiments, the method further includes adjusting an axis ofthe guide wire based on one or more conditions of a humeral head or softtissue structure.

There is provided a method of resurfacing a glenoid fossa, the methodcomprising: obtaining a three-dimensional scan of a scapula; identifyingpatient specific anatomy on the scapula; determining a desired location,inclination and version; fabricating a template based upon thethree-dimensional scan of the scapula, the identified patient specificanatomy and forming a guide on the template for receiving a guide wireat the desired location, inclination and version; mounting the templateonto the scapula; inserting the guide wire through the guide and intothe glenoid fossa; removing the template; inserting at least oneinstrument over the guide wire to prepare the glenoid for receiving animplant; removing the instrument and the guide wire; and mounting aglenoid implant to the glenoid fossa.

In some embodiments, the first piece of the guide is fabricated based onpatient specific anatomy selected from the group consisting of a face ofthe glenoid fossa, a diseased area on a face of the glenoid fossa, ananterior rim of glenoid, a posterior rim of glenoid, an inferior rim ofglenoid, a superior rim of glenoid, an infraglenoid tubercle, asupraglenoid tubercle, a scapula neck, a scapula blade, a coracoidspine, a scapula spine, a midpoint of the glenoid fossa, one or moresoft tissue structures, and combinations thereof.

In some embodiments the step of determining of at least one of theinclination and version further comprises: determining a desired centerpoint on the glenoid fossa; determining a plane of a glenoid of thescapula from the three-dimensional scan; and determining a line throughthe point and normal to the plane.

In some embodiments the step of determining inclination comprises:determining a first point at the intersection of the scapula spine andthe medial border of the scapula; determining a second point at themiddle of the spinoglenoid notch; determining a first line through thefirst and second points; determining a third point at the superiormargin of the glenoid fossa; determining a forth point at the inferiormargin of the glenoid fossa; determining a second line through the thirdand fourth points; and determining a desired inclination from an anglebetween the first and second lines.

In some embodiments the step of determining version comprises:determining a first point at an anterior margin of the glenoid fossa;determining a second point at the posterior margin of the glenoid fossa;determining a first line through the first and second points;determining a third point at the midpoint of the glenoid fossa;determining a forth point at the vertebral border of the scapula;determining a second line through the third and fourth points;determining a third line which is perpendicular to the second line; anddetermining a desired version from an angle between the first and thirdlines.

In some embodiments, the glenoid fossa is reamed prior to mounting theglenoid template onto the glenoid fossa.

There is provided a method for fabricating a two-piece drill guide forpreparing a glenoid fossa, the method comprising: obtaining athree-dimensional scan of a scapula; identifying patient specificanatomy on a scapula; determining a desired location, inclination andversion; fabricating a first piece of the drill guide based on thepatient specific anatomy; fabricating a second piece of the drill guidebased on the desired location, inclination and version; and coupling thefirst and second pieces of the drill guide.

In some embodiments, the first piece of the drill guide is fabricatedbased on patient specific anatomy selected from the group consisting ofa face of the glenoid fossa, a diseased area on a face of the glenoidfossa, an anterior rim of glenoid, a posterior rim of glenoid, aninferior rim of glenoid, a superior rim of glenoid, an infraglenoidtubercle, a supraglenoid tubercle, a scapula neck, a scapula blade, acoracoid spine, a scapula spine, a midpoint of the glenoid fossa, one ormore soft tissue structures, and combinations thereof.

In some embodiments, the first piece of the drill guide is coupled tothe second piece of the drill guide using a dovetail type or T-slot typeconnection that enables the second piece of the guide to move mediallywith respect to the first piece of the guide.

STATEMENTS OF THE INVENTION

One disclosed method of fabricating a template used in a resurfacingprocedure of a humeral head comprises:

-   -   identifying patient specific anatomy from a three-dimensional        scan of the proximal humerus;    -   determining at least one of a desired location, inclination and        retroversion;    -   fabricating a template based upon the three-dimensional scan of        the proximal humerus and the identified patient specific        anatomy; and    -   forming a guide on the template for receiving a guide wire at        the desired location, inclination and retroversion.

The disclosed methods may further comprise:

-   -   fabricating a cutting block for resecting the humeral head based        upon the three-dimensional scan of the proximal humerus and the        identified patient specific anatomy.

In the disclosed methods, the patient specific anatomy is selected fromthe group consisting of an articular surface, a diseased area on thearticular surface, a bicipital groove, a greater tubercle, a lessertubercle, a footprint of the greater tubercle, a metaphyseal axis, atrans-epicondylar axis, an anatomical neck, an anterior portion of theproximal humerus, a posterior portion of the proximal humerus, anosteophite, one or more soft tissue structures and combinations thereof.

In the disclosed methods, the determining of at least one of a desiredlocation, inclination and retroversion and further comprises:

-   -   determining a center point of the humeral head;    -   determining a plane of an anatomical neck of the proximal        humerus from the three-dimensional scan; and    -   determining a line through the center point and normal to the        plane.

In the disclosed methods, the determining of at least one of a desiredlocation, inclination and retroversion and further comprises:

-   -   determining a center point of the humeral head;    -   determining a plane of an anatomical neck of the proximal        humerus from the three-dimensional scan;    -   determining a line through the center point and normal to the        plane;    -   determining a metaphyseal axis from the three-dimensional scan;        and    -   determining a desired inclination from an angle between the line        and the metaphyseal axis.

In the disclosed methods, the determining of at least one of a desiredlocation, inclination and retroversion and further comprises:

-   -   determining a center point of the humeral head;    -   determining a plane of an anatomical neck of the proximal        humerus from the three-dimensional scan;    -   determining a line through the center point and normal to the        plane;    -   determining a distal trans-epicondylar axis from an image of the        humerus; and    -   determining a desired retroversion from an angle between the        line and the distal trans-epicondylar axis.

In the disclosed methods, the determining of at least one of a desiredlocation, inclination and retroversion and further comprises:

-   -   determining a desired retroversion and a distal        trans-epicondylar axis from a superior-inferior x-ray of the        humeral head;    -   determining a desired retroversion from the superior-inferior        x-ray and the three-dimensional image of the humeral head.

The disclosed methods may further comprise adjusting an axis of theguide wire based on one or more conditions of a glenoid fossa.

Another disclosed method for fabricating a glenoid template forinserting a guide wire at a desired trajectory during a resurfacing of aglenoid fossa comprises:

-   -   identifying patient specific anatomy on a scapula from a        three-dimensional scan of the scapula;    -   determining a plane of the glenoid fossa from the        three-dimensional scan of the scapula;    -   determining a desired location, inclination and version from the        three-dimensional scan of the scapula;    -   fabricating the glenoid template based upon the        three-dimensional scan of the scapula and the identified patient        specific anatomy; and    -   forming a guide on the glenoid template for receiving the guide        wire at the desired location, inclination and version.

In the disclosed methods, a first piece of the guide is fabricated basedon patient specific anatomy selected from the group consisting of a faceof the glenoid fossa, a diseased area on a face of the glenoid fossa, ananterior rim of glenoid, a posterior rim of glenoid, an inferior rim ofglenoid, a superior rim of glenoid, an infraglenoid tubercle, asupraglenoid tubercle, a scapula neck, a scapula blade, a coracoidspine, a scapula spine, a midpoint of the glenoid fossa, one or moresoft tissue structures, and combinations thereof.

In the disclosed methods, the determining of the desired location,inclination and version may further comprise:

-   -   determining a first point at an intersection of a scapula spine        and a medial border of the scapula from the three-dimensional        scan of the scapula;    -   determining a second point at the middle of a spinoglenoid notch        from the three-dimensional scan of the scapula;    -   determining a first line through the first and second points;    -   determining a third point at a superior margin of the glenoid        fossa from the three-dimensional scan of the scapula;    -   determining a forth point at an inferior margin of the glenoid        fossa from the three-dimensional scan of the scapula;    -   determining a second line through the third and fourth points;        determining a desired inclination from an angle between the        first and second lines.

In the disclosed methods, the determining of the desired location,inclination and version may further comprise:

-   -   determining a first point at an anterior margin of the glenoid        fossa from the three-dimensional scan of the scapula;    -   determining a second point at a posterior margin of the glenoid        fossa from the three-dimensional scan of the scapula;    -   determining a first line through the first and second points;    -   determining a third point at the midpoint of the glenoid fossa        from the three-dimensional scan of the scapula;    -   determining a forth point at a vertebral border of the scapula        from the three-dimensional scan of the scapula;    -   determining a second line through the third and fourth points;    -   determining a third line, which is perpendicular to the second        line; and    -   determining a desired version from an angle between the first        and third lines.

A template used in a resurfacing procedure of a humeral head of ahumerus is disclosed. One disclosed template comprises:

-   -   the template covering at least part of the humeral head and a        patient specific anatomy disposed on a proximal humerus of the        humerus, the template having a negative geometry that matches a        positive geometry of the at least part of the humerus and the        patient specific anatomy covered by the template;    -   the template comprising a guide for receiving a guide wire at a        desired location, inclination and retroversion.

A cutting block for use with above-described template is disclosed. Thedisclosed cutting block comprises:

-   -   the cutting block mounted to the humeral head and comprising an        upper cutting surface disposed at a desired resection angle, the        block extending below the upper cutting surface and covering        patient specific anatomy disposed on the proximal humerus;    -   the cutting block having a negative geometry that matches a        positive geometry of the patient specific anatomy on the        proximal humerus and a portion of the humeral head disposed        between the patient specific anatomy on the proximal humerus and        the upper cutting surface of the cutting block.

A template used in a resurfacing procedure of a glenoid fossa disposedon a scapula is disclosed. The disclosed template comprises:

-   -   the template covering at least part of the glenoid fossa and a        patient specific anatomy disposed on the scapula, the template        having a negative geometry that matches a positive geometry of        the at least part of the glenoid fossa the and patient specific        geometry of the scapula covered by the template;    -   The template comprising a guide for receiving a guide wire at a        desired location, inclination and version.

Further areas of applicability of the invention will become apparentfrom the detailed description provided hereinafter. It should beunderstood that the detailed description and specific examples, whileindicating the particular embodiment of the invention, are intended forpurposes of illustration only and are not intended to limit the scope ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part ofthe specification, illustrate the embodiments of the invention andtogether with the written description serve to explain the principles,characteristics, and features of the invention. In the drawings:

FIGS. 1-2 illustrate a humeral head template and guide fabricated usinga 3D scan;

FIG. 3 illustrates the humeral head template of FIGS. 1-2 that providesclearance for soft tissue;

FIG. 4 illustrates the humeral head template of FIGS. 1-3 whereby thepartial footprint of the greater tuberosity and the biceps groove areused to hold the template in place;

FIG. 5 is another view of the template of FIG. 4 further illustratingthe use of a diseased area on an articular surface of the humeral headalong with the biceps groove and partial footprint of the greatertuberosity to hold the template in place during insertion of the guidewire;

FIG. 6 is a top view of the humeral head template of FIGS. 1-5illustrating patient specific retroversion from the transepicondylaraxis of the distal humerus;

FIG. 7 is a plan view of the humeral head template of FIGS. 2-7illustrating patient specific inclination derived from an axisperpendicular to the metaphyseal axis;

FIG. 8 is a schematic illustration of an x-ray taken from the superiorside of the humeral head towards the transepicondylar axis at the elbowwhich has been marked;

FIG. 9 illustrates a disclosed cutting block installed on the humeralhead that is held in place by patient specific geometries derived from a3D scan;

FIG. 10 is a top view of the cutting block illustrated in FIG. 9 ;

FIG. 11 is an illustration of another cutting block that makes use ofpatient specific geometries and that is provided with a hinge;

FIG. 12 is a two-part block with an upper portion connected to a cuttingblock via a dovetail connection wherein the upper portion is used as aguide to place the lower cutting block in place while the resectiontakes place along the anatomical neck of the humerus;

FIG. 13 is a partial sectional view of a cutting block apparatus used ina reverse shoulder implant procedure wherein the lower portion isanchored to the metaphyseal shaft and pins are used to hold the cuttingblock in place as the humeral head is resected at a 155° angle withrespect to the transverse plane;

FIG. 14 illustrates an embodiment similar to that shown in FIG. 13wherein the cutting block is equipped with an orientation pin that canadjust the cutting block with respect to the axis of the forearm;

FIGS. 15-16 illustrate the position of the patient while utilizing theapparatuses illustrated in FIGS. 13-14 ;

FIGS. 17-20 illustrate the installation of a cutting block utilizingpatient specific geometry proximal to the anatomical neck of the humeralhead for the purpose of providing a resection plane;

FIG. 21 illustrates yet another humeral head resection apparatus whereina lower cutting block is connected distally of the greater tubercle andincludes a proximal portion that stabilizes the cutting block based onproximal negative geometry of the humeral head and further provides a155° angle between the resection plane and the transverse plane for areverse implant procedure.

FIG. 22 is a top view of the apparatus of FIG. 21 ;

FIG. 23 illustrates yet another cutting block apparatus for a reverseimplant procedure that is two-part with an upper or proximal portionconnected to a lower or distal cutting block with a dovetail-typeconnection;

FIG. 24 is a top view of the cutting block and humeral templateillustrated in FIG. 23 .

FIGS. 25-27 illustrate a proximal humeral head template (FIG. 25 ) andtwo cutting blocks that may be connected to the humeral head templatevia a dovetail-type connection wherein the surgeon may not be able toassess the deficiency of the rotator cuff preoperatively and thereforethe cutting block of FIG. 26 can be used for a standard shoulder implantprocedure and the cutting block of FIG. 27 can be used for a reverseshoulder implant procedure;

FIG. 28 illustrates a cutting block that is stabilized using lateralpatient specific geometry;

FIG. 29 schematically illustrates a jig for holding the patient'shumerus, forearm and wrist in a proper position for carrying out thesuperior-inferior x-ray of FIG. 8 ;

FIG. 30 illustrates a glenoid fossa that has been marked with thesuperior-inferior and anterior-posterior axes intersection for placementof a guide wire in a standard shoulder implant procedure;

FIG. 31 illustrates the placement of a glenoid block and guide or bossfor a guide wire on a glenoid illustrating the position of the guide ata 90° angle with respect to the plane of the original pre-diseaseglenoid face;

FIGS. 32-33 illustrate the use of patient specific geometry alonginferior portions of the glenoid fossa and scapular neck for supportingthe glenoid block of FIG. 31 ;

FIG. 34 illustrates various patient specific geometries that can be usedto stabilize the glenoid block of FIGS. 31-33 including the glenoid faceas a medial hard stop, anterior and posterior faces of the glenoid asposterior or anterior hard stops respectively and a portion of thescapular neck as a superior hard stop;

FIGS. 35-36 illustrate the placement of a glenoid block and guide andthe use of a posterior face of the glenoid as an anterior hard stop, theface of the glenoid as a medial hard stop, and a portion of the scapularneck as a superior hard stop;

FIGS. 37-38 illustrate a glenoid block and guide and the use of ananterior face of the glenoid as a posterior hard stop, the face of theglenoid as a medial hard stop and a portion of the scapular neck as asuperior hard stop;

FIGS. 39-40 illustrate a glenoid block and guide and the use of the faceof the glenoid as a medial hard stop and a portion of the scapular neckas an anterior-posterior hard stop and a superior hard stop;

FIGS. 41-42 illustrate a variation of the embodiment shown in FIGS.39-40 , wherein a glenoid block and guide are shown and the glenoidblock uses of the face of the glenoid as a medial hard stop and aportion of the scapular neck as an anterior-posterior hard stop andsuperior hard stop;

FIGS. 43-44 illustrate a glenoid block and guide wherein an arm of theglenoid block uses of a junction of the coracoid and glenoid face as ananterior and inferior hard stop;

FIG. 45 is an illustration of a glenoid fossa marked with theintersection of a superior-inferior axis and a posterior-anterior axisand with an appropriate entry point for a guide wire in aposterior-inferior quadrant of the glenoid fossa for a reverse shoulderimplant procedure;

FIG. 46 illustrates a glenoid block and guide attached to a glenoid witha about 10° of inferior inclination provided by the guide for a reverseshoulder implant procedure;

FIGS. 47-48 illustrate the placement of glenoid blocks with guides foruse in a reverse shoulder implant procedure and the glenoid block ofFIG. 48 illustrates the use of an additional reference hole foralignment purposes;

FIG. 49 is a sectional view of a scapula, glenoid base plate and lockingscrews that are the result of 3D images, surgeon review, engineerscreating a virtual model of the patient's scapula, additional surgeonreview and the creation of a best-fit 3D model created by both surgeonsand engineers to avoid a locking screw extending through scapulacortical bone or a “breakout” situation;

FIG. 50 is an illustration of a glenoid block on a glenoid fossa;

FIG. 51 illustrates glenoid block of FIG. 50 after insertion of theguide wire guide or boss;

FIG. 52 is a bottom view of the scapular spine and glenoid blockillustrated in FIG. 51 ;

FIG. 53 is an illustration of a guide wire inserted through the guide orboss of the glenoid block illustrated in FIGS. 55-52 ;

FIG. 54 illustrates the guide wire inserted into the glenoid fossa afterremoval of the guide or boss illustrated in FIG. 53 ;

FIG. 55 illustrates the guide wire extending out of the glenoid fossaafter removal of the glenoid block shown in FIGS. 50-54 ;

FIGS. 56-57 illustrate the guide wire extending out of the glenoid fossabefore (FIG. 56 ) and after reaming (FIG. 57 );

FIG. 58 illustrates the installation of an inferior bone screw drillguide of a two-piece drill guide at the inferior end of a glenoid fossa;

FIG. 59 illustrates the coupling of superior bone screw drill guide tothe inferior bone screw drill guide illustrated in FIG. 58 using adovetail-type to T-slot coupling arrangement;

FIGS. 60-61 illustrate the coupling of drill guides to the superior bonescrew drill guide shown in FIG. 59 for drilling peripheral screw holes;

FIG. 62 is a front plan view of the inferior bone screw drill guide andsuperior bone screw drill guide shown in FIGS. 58-61 ;

FIG. 63 illustrates the central hole drilled over the guide wire and theperipheral holes drilled through the superior bone screw drill guideprior to installation of the glenoid base plate;

FIGS. 64-66 illustrate the installation of the glenoid base plate andlocking screws;

FIGS. 67-69 illustrate a successful installation of a glenoid base plateand locking screws using the techniques disclosed herein withoutbreakout or without the screws passing through the cortical structure ofthe scapula;

FIGS. 70-71 are side views of the glenoid block 310 before and afterreaming of the glenoid fossa;

FIG. 72 is a side view of a disclosed two-piece bone screw drill guideillustrating a need for medial-lateral degree of freedom provided by thedisclosed two-piece bone screw drill guide; and

FIG. 73 is a front view of a two-piece drill guide that can be used instandard shoulder implant procedures where the glenoid implant includesa central peg and three peripheral pegs that are cemented to the glenoidfossa.

DETAILED DESCRIPTION

The following description of the depicted embodiment(s) is merelyexemplary in nature and is in no way intended to limit the invention,its application, or uses.

Humeral Head Resurfacing and Humeral Head Templates

Disclosed methods and devices for resurfacing humeral heads are shownand described in FIGS. 1-12 . Turning to FIGS. 1-2 , the humeral head100 is imaged using a computerized axial tomography (CAT or CT) scan ora magnetic resonance image (MRI) or other suitable 3D scanning method.The 3D scan is used to provide patient specific anatomy that can be usedto generate a custom humeral head template 145 that may be equipped witha guide 146 for receiving a guide wire. The guide 146 and humeral headtemplate 145 may be fabricated separately or as a unitary structure. Theamount of patient-specific anatomy that can be used to stabilize thehumeral head template 145 may be determined by the surgeon or may bestandardized based upon future established procedures or by themanufacturer. Patient-specific anatomy that can be used to stabilize thehumeral head template 145 in place may include, but is not limited tothe following: an articular surface; a diseased area on an articularsurface; a bicipital groove; a greater tuberosity; a lesser tuberosity;a footprint of the greater tuberosity; the metaphyseal axis; theanatomical neck of the humeral head 100; an anterior humeral head; aposterior humeral head; an anterior surgical neck; a posterior surgicalneck; soft tissue structures; and combinations thereof.

For example, the greater tuberosity 147 and lesser tuberosity 148 can bepartially seen in FIG. 3 . A portion of the bicipital groove 149 canalso be seen in FIG. 3 . Turning to FIG. 4 , a partial footprint 151 ofthe greater tuberosity or greater tubercle is created in the customizedhumeral head template 145 as a ridge 152 that corresponds to thebicipital groove 149. Additional views of the footprint 151 and ridge152 are provided in FIG. 5 . In addition, FIG. 5 illustrates a pattern153 that represents a negative geometry of a diseased area on anarticular surface of the humeral head 100.

Turning to FIGS. 6-7 , the 3D scan of the proximal humerus or humeralhead 100 can be used to insure that the guide wire is placed in theoptimal location in the center of the humeral head 100. An optimal guidewire location corresponds to an optimal implant fit. Thus, a desiredinclination and retroversion can be determined in large part bypatient-specific anatomy and discussed with the surgeon prior tofabricating the humeral head template 145. For example, the humeral headtemplate 145 is designed with the patient-specific retroversion angle θ,which is determined by the transepicondylar axis 150 of the distalhumerus 156 and a line 157 that bisects the humeral head 100. The guidewire will be inserted through the guide 146 along the line 157. Theextent of the humeral torsion or retroversion typically ranges fromabout 20° to about 40°. A superior-inferior x-ray as illustrated in FIG.8 can be used to determine the angle θ between the transepicondylar axis150 and the coronal plane 104 for purposes of determining theretroversion preoperatively.

Turning to FIG. 7 , the inclination Ω is the angle between theanatomical neck and the coronal plane 104. The inclination angle Ω canrange from about 120° to about 150° as indicated in FIG. 7 . Thetransverse plane is indicated at 105.

The humeral head template 145 and guide 146 are fabricated usingcurrently available computer aided design (CAD) programs and finiteelement analysis (FEA) software based upon the data taken from the 3Dscan of the humerus, which may be a CT, MRI, or other suitable scan. Forexample, once a profile is fixed in space in a 3D model of a humeralhead 100, a humeral head template 145 may be created having a negativeprofile and superimposed on the 3D model of the humeral head 100.Available software may perform iterative test runs to predict whethersmall adjustments to the position of the humeral head template 145 arenecessary to optimize performance. The fabrication of the humeral headtemplate 145 may be performed before or after the humeral head 100 isreamed. It may be preferable to ream the humeral head 100 after theguide wire 106 is inserted through the guide 146.

One advantage to using a CT scan or MRI for only the humeral head 100 orproximal portion of the humerus is to limit the radiation exposure tothe patient. By employing a combination of a 3D image and a standardx-ray as illustrated in FIG. 8 , the radiation exposure to the patientis minimized. In short, the disclosed method uses a minimal amount of 3Dscanning in conjunction with an axial x-ray to establish the desiredretroversion.

After the guide wire 106 is inserted through the guide 146, the humeralhead template 145 and guide 146 may be removed and the humeral head 100reamed to a spherical shape for receiving an implant. As an alternative,3D imaging in combination with CAD and FEA software may be employed tocreate patient-specific humeral cap implants produced to match theirregularly shaped humeral heads.

In any case, the methods described above enable the surgeon to determineretroversion and inclination preoperatively. The above methods andcustomized humeral head template 145 provides stability for the preciseplacement of the guide wire through the guide 146. As a result, optimalspherical implant 109 positioning on a non-spherical humeral head 100can be achieved.

Humeral Head Resection and Patient Specific Cutting Blocks

For more severe cases, resection of the humeral head 100 is required.Various apparatuses or tools and techniques for resecting a humeral head100 will be described below in connection with FIGS. 9-29 . Turningfirst to FIG. 9 , a 3D scan of a humeral head 100 has been taken and acutting block 165 has been fabricated that exploits patient-specificgeometries of the anterior, superior and inferior portions of thehumeral head 100 that may include, but are not limited to tuberositites,osteophytes, the biceps groove, soft tissue insertion points, etc. Theabove geometry is typically located distally to the anatomical neck 166.The cutting block 165 could also be generated from any combination ofanterior, posterior, inferior and superior anatomy. Only one cuttingblock 165 is required for a resection. Divergent or convergent pinholes167 may be employed for receiving bone spikes, trocar pins, speed pinsor bone screws to secure the cutting block 165 to the humeral head 100.An extended surface 168 provides a guide for the blade of the saw (notshown). Alternatively, the cutting block 165 may incorporate a slot forthe saw blade. The patient-specific geometry, or more precisely, anegative of the patient-specific geometry, is disposed along the insidesurface 169 of the cutting block 165.

In another embodiment shown in FIG. 11 , a cutting block 171 is providedthat includes two pieces 172, 173 that are hingedly connected togetheraround the anatomical neck 166. Because the patient-specific anatomyalone should prevent the block 171 from slipping or moving, pinholeslike those shown at 167 in FIG. 10 may not be needed although could beincluded, if desired. A negative patient-specific geometry of theanterior, superior and inferior portion of the humeral head may beincluded and may accommodate tuberositites, osteophytes, soft tissueinsertion points, the bicep groove and other landmarks. The block 171 isparticularly useful for patient-specific geometry located just distal tothe anatomical neck 166. Screw hinges 175 may be employed as well as anextended surface like the one shown at 168 in FIG. 10 . The embodimentsof FIGS. 9-11 exploit patient-specific geometry located distally to theplane of the anatomical neck 166. Patient-specific geometry locatedproximally to the plane of the anatomical neck 166, such as the humeralhead articular surface, may also be used alone or in combination withthe above-referenced distal patient-specific geometry. For example,referring to FIG. 12 , a dual piece block 177 includes a proximal piece178 that partially covers the proximal humeral head and a lower cuttingblock piece 179 connected to the proximal piece 178 with a dovetail orT-slot type connection. A surface provides a guide for the blade of thesaw. Alternatively, the cutting blocks 171, 177 may incorporate a slotfor the saw blade.

For reverse shoulder implants, a cutting block 181 that exploits theflute of the metaphyseal shaft 183 may be employed that provides a fixedresection angle of 155°, or the angle between the cutting surface 184and the transverse plane 105. The resection angle of 155° is standardfor reverse shoulder implants. A surface provides a guide for the bladeof the saw. Alternatively, the cutting block may incorporate a slot forthe saw blade. A threaded orientation pin is shown at 185 and additionalpins 186 may be used to secure the cutting block 181 to the humeral head100. The threaded orientation pin 185 is also illustrated in FIG. 14 ,which allows the surgeon to confirm his/her orientation by aligning thepin with the forearm axis 187 as shown in FIG. 15 . FIGS. 14-15 alsoillustrate the transepicondylar axis 150. The position of the patientduring the resection procedure is illustrated in FIG. 16 .

Another type of block 190 that relies upon patient specific anatomygenerated from 3D scans just distal to the resection plane isillustrated in FIGS. 17-20 . The block 190 utilizes pins or screws 191and pinholes 192 to hold the block 190 in place during the resectionprocedure. The flat surface 193 serves as a convenient cutting guide.Alternatively, the cutting block 190 may incorporate a slot for the sawblade. One-piece or dual-piece block combinations can be utilized.

An additional one-piece cutting block 195 is illustrated in FIGS. 21-22, which includes a threaded orientation, pin 185 and additionalstabilizing pins 186. A dual-piece configuration 195 a is illustrated inFIGS. 23-24 . The lower portions 196 include flat surfaces 197 that areused as cutting guides. Alternatively, the cutting block 195 mayincorporate a slot for the saw blade.

In certain cases, the surgeon may not be able to assess the deficiencyof the rotator cuff until he or she has opened the patient and exposedthe shoulder. In these situations, a decision as to whether to utilize astandard shoulder implant or a reverse shoulder implant may have beendelayed. Because reverse shoulder implants include a 155° resection ofthe humerus, and a standard shoulder implant includes a lesser resectionangle, e.g. 135°, a single upper portion 195 b (FIG. 25 ) may beemployed with two lower portions 196 b (FIG. 26 ), 196 c (FIG. 27 ). Thelower portion 196 b may be used for a standard shoulder implant andprovides a resection angle of about 135°. The lower portion 196 c may beused for a reverse shoulder implant and provides a resection angle of155°. The upper portion 195 b can be connected to the lower portions 196b or 196 c using the dovetail-type connection shown in FIGS. 25-27 or aT-slot connection or similar connection means.

Turning to FIG. 28 , the cutting block 198 exploits lateralpatient-specific negative geometry at the greater tuberosity 147 and issecured in place with a pin 199. A single pin 199 or multiple pins thatare either convergent or divergent may be utilized. The amount ofretroversion can be established using the procedure discussed below inconnection with FIG. 8 .

In FIG. 29 , a jig 200 is provided for the 3D scanning step and theaxial x-ray step in order to insure that the humerus is parallel to thelong axis of the scanner and to insure that the elbow is flexed at 90°.The jig 200 may aid in the determination of variables, such as versionor inclination. Additionally, the jig may be used to consistentlymeasure and compare anatomy. For example, anatomy could be measured andcompared to predict usable instrumentation and/implants. The jig 200 isillustrated with a first plate 201 and strap 202 for holding theproximal humerus and a second plate 203 and straps 204, 205 for holdingthe elbow and hand/wrist or fingers respectively. If the patient is ableto maintain his/her forearm in a vertical position, the vertical line207 represents the forearm axis. The straps 202, 204, 205 can befabricated from Velcro™, elastic, etc. A pistol or barrel grip 208 maybe more comfortable and preferred by the patient. In some embodiments,the jig may include one or more markers that are visible by 3D scanningand/or x-ray.

Glenoid Fossa Resurfacing—Standard and Reverse Shoulder Implants

FIG. 30 illustrates a technique for choosing a template that providesoptimal coverage of the glenoid fossa 210. The center of the templatenormally corresponds with the optical center of the glenoid fossa 210.In order to establish optimal insertion of the guide wire using thetechniques disclosed herein, the intersection of a superior-inferioraxis 216 and anterior-posterior axis 217 provides an optical center 218which may provide an optimal insertion position for the guide wireduring a standard shoulder implant procedure. For anatomicalreconstruction, the glenoid fossa 210 should be reamed perpendicular tothe original, non-diseased, face of the glenoid fossa 210. FIG. 31illustrates the use of the 3D image to approximate the original plane219 of the glenoid fossa 210. Returning to FIG. 30 , variouspatient-specific anatomical features can be used for stabilizing aglenoid block 225 (FIG. 31 ) which will be used for insertion of a guidewire 106. Those patient-specific anatomical features include thecoracoid 212, various features of the scapula 211 including the scapularspine 215 and portions of the acromion 213. Additional features forstabilizing a glenoid block 225 are also illustrated in FIG. 34 , whichinclude an anterior margin 226, a posterior margin 227, the lateral face229 of the glenoid fossa 210 and the superior portion 228 of thescapular spine 215.

FIGS. 31-34 relate to glenoid blocks that may be used in both standardand reverse shoulder implant procedures. FIG. 31 illustrates theinstallation of a glenoid block 225 with a guide 230 that isperpendicular to the original plane 219 of the pre-diseased glenoidfossa 210. The coracoid and acromion are shown at 212, 213 respectively.The wide variety of patient-specific anatomical features that can beused to anchor or stabilize a glenoid block 225 will be illustrated inFIGS. 32-44 below.

Turning to FIGS. 32-34 , the superior portion 228 of the scapular spine215 and inferior margin 231 of the glenoid fossa 210 are used to supportthe glenoid block 225. Because the glenoid block 225 illustrated inFIGS. 32 and 33 extends around the anterior and posterior side of theglenoid fossa 210, the anterior margin 226 and the posterior margin 227(FIG. 34 ) provide posterior and anterior hard stops respectively. Thesuperior portion 228 of the scapular spine 215 provides a superior hardstop. The lateral face of 229 of the glenoid fossa 210 provides a medialhard stop.

Turnings FIGS. 35-36 , a glenoid block 235 engages the posterior side ofthe glenoid fossa 210 and a portion of the scapular spine 215. The slot236 or narrow wall shown in FIG. 36 provides an anterior hard stop forthe block 235. The surface 237 engages the lateral face of the glenoidfossa 210 and therefore provides a medial hard stop. The surface 238(FIG. 36 ) that engages the scapular neck provides a superior hard stop.

Turning to FIG. 37-38 , the glenoid block 245 engages primarily theanterior side of the glenoid fossa 210 and therefore the slot or wall236 a (FIG. 38 ) provides a posterior hard stop, the face 237 a providesa medial hard stop and the surface 238 a provides a superior hard stop.

Turning to FIGS. 39-40 , an additional glenoid block 255 is disclosedwherein portions of the block 255 engage inferior portions of theanterior and posterior sides of the glenoid fossa 210 as well as asuperior portion of the scapular neck. Thus, turning to FIG. 40 , thesurface 237 b provides a medial hard stop and the shaped slot or groove238 b provides an anterior, posterior and superior hard stop for theglenoid block 255.

A similar embodiment is illustrated in FIGS. 41-42 where the face 237 cengages the face of the glenoid fossa 210 and provides a medial hardstop and the shaped slot 238 c provides an anterior, posterior andsuperior hard stop.

A different technique is employed in FIGS. 43-44 wherein the glenoidblock 275 includes an arm 276 that engages a junction of the coracoidand the glenoid fossa 210 to provide an anterior and posterior hardstop. The face 238 d of the block 275 provides a medial hard stop.

Turning to reverse shoulder implant procedures and FIGS. 45-73 , it isoften recommended that the surgeon install the glenoid base plate in aslightly inferior and posterior position shown at 218 a of FIG. 45 .This placement of the guide wire and base plate is intended to minimizescapular notching. Therefore, the target 218 a illustrated in FIG. 45 isdisposed slightly below the anterior-posterior axis 217 and slightlyposterior to the superior-inferior axis 216. Further, as shown in FIG.46 , it is sometimes optimal to apply a slight downward or inferior tiltto the guide wire and therefore FIG. 46 illustrates a non-perpendicularrelationship between the guide 232 and the original plane 219 of theglenoid fossa 210.

FIGS. 47-48 illustrate placement of the glenoid block 285 and guide 232to a glenoid fossa 210 with about a 10° of inferior inclination providedby the guide 232. FIG. 48 also illustrates the use of an additionalreference hole 286 for alignment purposes. The reference hole isintended to help prevent rotation of the glenoid base plate 285 duringinstallation, which could cause one of the locking screws to extendthrough the cortical bone structure of the scapula 211.

The glenoid blocks 225, 235, 245, 255, 265, 275 and 285 illustrated inFIGS. 31-48 provide stable, inexpensive, disposable and patient-specificmeans for accurately placing a guide wire in a glenoid fossa 210 duringboth standard and reverse shoulder implant procedures. Preoperativedetermination of the optimal inclination and glenoid block version andpossible use of a downward tilt on the guide wire are also possible sothat fewer crucial decisions are made during surgery.

Glenoid Fossa Resurfacing for Reverse Shoulder Implants

FIG. 49 is a sectional view of a best-fit virtual model created from 3Dimages, surgeon review and engineers creating the virtual model withadditional input from the surgeon. The sectional mage of FIG. 49 shows ascapula 211, glenoid base plate 136 and divergent locking screws 134,135. The creation of the model illustrated in FIG. 49 is intended toavoid locking screws 134, 135, which should be long as possible forstability and strength, from extending through the cortical bonestructure of the scapula 211, or in other words, creating a “breakout”situation. Methods and devices for creating the best-fit modelillustrated in FIG. 49 are illustrated in FIGS. 50-73 .

Turning to FIG. 50 , a glenoid block 310 is installed over a glenoidfossa 210. A boss or guide 311 is inserted into the block 310 inpreparation for insertion of a guide wire. A bottom view of the block310 and guide 311, which are stabilized on the scapular spine 215 and inthe posterior and anterior directions is shown in FIG. 52 . FIG. 53illustrates insertion of the guide wire 206 into the guide 311. FIG. 54illustrates removal of the guide 311 and FIG. 55 illustrates removal ofthe glenoid block 310. FIGS. 56-57 illustrate the glenoid fossa 210before reaming (FIG. 56 ) and after reaming (FIG. 57 ).

Two-Piece Drill Guides

FIG. 58 illustrates the central hole 138 that receives the central peg137 of the glenoid base plate. The central hole 138 is created by usinga cannulated drill over the guide wire 206. FIGS. 58-59 also illustratethe installation of a two-piece bone screw drill guide 319 that includesa lower piece, referred to as the inferior bone screw drill guide 320(FIG. 58 ) and an upper piece, referred to as the superior bone screwdrill guide 322 that is slidably coupled to the inferior bone screwdrill guide 320. The inferior bone screw drill guide 320 is installed onthe infraglenoid tubercule and scapular spine 215 and includes a T-slotor dovetail-type connection for a slidable connection to a superior bonescrew drill guide 322 as illustrated in FIG. 59 . The T-slot ordovetail-type connection enables the superior bone screw drill guide tobe adjusted laterally with respect to the face of the glenoid fossa 210.FIGS. 60-61 illustrate the coupling of drill guides 323 to the superiorbone screw drill guide 322 for drilling divergent locking screw holes inthe scapula 211. FIG. 62 illustrates the prepared screw holes 324, 325through the superior bone screw drill guide 322 in preparation forreceiving locking screws. FIG. 63 illustrates removal of the superiorbone screw drill guide 322 and inferior bone screw drill guide 320leaving the screw holes 324, 325 and central hole 138. FIG. 64illustrates the installation of the glenoid base plate with the centralpeg 137 (FIG. 101 ) inserted into the central hole 138. FIGS. 65-66illustrate the installation of the locking screws 134, 135.

Turning to FIGS. 67-69 , sectional views illustrate an optimalinstallation of a glenoid base plate 136 without either locking screw134 or 135 entering the cortical bone structure of the scapula 211.

FIGS. 70-71 illustrate side views of the glenoid block or guide wireplacement block 310 before and after reaming of the glenoid fossa 210and the need for the medial-lateral degree of freedom provided by thetwo-piece bone screw drill guide 319. FIG. 72 further illustrates theadvantage of the medial-lateral adjustability of the superior bone screwdrill guide 322 with respect to the inferior bone screw drill guide 320for more accurate placement of the holes used to anchor the lockingscrews 134, 135.

FIG. 73 illustrates a two-piece drill guide 319 a that may be used forstandard glenoid implants. Similar to the two-piece bone screw drillguide 319 used for reverse shoulder implant procedures, the inferiordrill guide 320 a for a standard implant is installed on theinfraglenoid tubercule and scapular spine 215 and includes a T-slot ordovetail-type connection for a slidable connection to a superior drillguide 322 a that includes peripheral drill holes 334 that match thepattern of the peripheral pegs.

Images like those shown in FIGS. 30-73 can be presented to a surgeon forreview preoperatively so that the surgeon may pay close attention to theresulting orientation and position of the glenoid base plate 136 orglenoid implant 136 a and lengths of the locking screws 134, 135 if areverse implant procedure is planned. After approving the models likethose shown in FIGS. 30-73 , the surgeon may then place an order andpatient-specific instruments as shown in FIGS. 30-73 are fabricatedprior to surgery.

In some cases, the surgeon may not be able to assess the deficiency ofthe rotator cuff until surgery has begun. In these cases, multipleglenoid blocks may be provided and multiple superior bone screw drillguides may be provided that would allow the surgeon to implant a glenoidbase plate 136 or a glenoid implant 136 a that may be cemented in placewithout the need for locking screws. The disclosed methods alsoeliminate many freehand placement and orientation procedures includingfreehand placement of the guide wire, orientation and placement of thedrill guides. The disclosed methods also substantially reduce thepossibility of drilling too deep or using locking screws that couldextend through cortical bone structure in reverse implant procedures.

As various modifications could be made to the exemplary embodiments, asdescribed above with reference to the corresponding illustrations,without departing from the scope of the invention, it is intended thatall matter contained in the foregoing description and shown in theaccompanying drawings shall be interpreted as illustrative rather thanlimiting. Thus, the breadth and scope of the invention should not belimited by any of the above-described exemplary embodiments, but shouldbe defined only in accordance with the claims and their equivalents.

What is claimed is:
 1. A method for fabricating a glenoid template for areverse shoulder implant procedure, the method comprising: providingsoftware to allow a user to appropriately position a glenoid componentof a reverse shoulder implant assembly; receiving a scan of a glenoidcavity of a patient's scapula including patient specific anatomy of theglenoid cavity; virtually enabling the glenoid component to bepositioned on the scan of the glenoid cavity so that the glenoidcomponent avoids inserting a locking screw through the patient'sscapula; and fabricating the glenoid template based upon the positioningof the glenoid component, the glenoid template being arranged andconfigured to receive a guide wire at a pre-operatively determinedlocation to assist a surgeon during the reverse shoulder implantprocedure.
 2. The method of claim 1, wherein the scan is a CT (CAT)scan.
 3. The method of claim 1, wherein the scan is an MRI scan.
 4. Themethod of claim 1, wherein the glenoid template includes an opening toreceive a guide, the guide being arranged and configured to receive theguide wire therethrough.
 5. The method of claim 1, further comprising:mounting the glenoid template onto the glenoid cavity; and inserting theguide wire into the glenoid cavity.
 6. The method of claim 5, furthercomprising using the guide wire to drill a hole in the glenoid cavity toreceive a post of the glenoid component.
 7. The method of claim 5,further comprising inserting at least one instrument over the guide wireto prepare the glenoid cavity for receiving the glenoid component. 8.The method of claim 7, further comprising: removing the glenoidtemplate; removing the instrument and the guide wire; and implanting theglenoid component into the glenoid cavity.
 9. A method for fabricating aglenoid template for a reverse shoulder implant procedure, the methodcomprising: obtaining a scan of a glenoid cavity of a patient's scapulato identify patient specific anatomy of the glenoid cavity; determininga position of a glenoid component of a reverse shoulder implant assemblybased on the scan including positioning the glenoid template to avoidinserting a screw through the patient's scapula; deriving the glenoidtemplate based upon the scan of the glenoid cavity and the determinedposition of the glenoid component; and fabricating the glenoid template,the glenoid template being arranged and configured to receive a guidewire at a desired location to assist a surgeon during the reverseshoulder implant procedure.
 10. The method of claim 9, whereindetermining the position of the glenoid component is performed virtuallyon the scan.
 11. The method of claim 9, wherein the scan is a CT (CAT)scan.
 12. The method of claim 9, wherein the scan is an MRI scan. 13.The method of claim 9, wherein the glenoid template includes an openingto receive a guide, the guide being arranged and configured to receivethe guide wire therethrough.
 14. The method of claim 9, wherein derivingthe glenoid template comprises aligning a center of the glenoid templatewith an optical center of the glenoid cavity, the optical center of theglenoid cavity corresponds with an intersection of a superior-inferioraxis and an anterior-posterior axis.
 15. The method of claim 9, furthercomprising: mounting the glenoid template onto the glenoid cavity;inserting the guide wire into the glenoid cavity; and inserting at leastone instrument over the guide wire to prepare the glenoid cavity forreceiving the glenoid component.
 16. The method of claim 15, wherein theat least one instrument is a drill configured to drill a hole in theglenoid cavity to receive a post of the glenoid component.
 17. Themethod of claim 15, further comprising: removing the glenoid template;removing the instrument and the guide wire; and implanting the glenoidcomponent into the glenoid cavity.
 18. A method for fabricating aglenoid template for a reverse shoulder implant procedure, the methodcomprising: obtaining a CT scan of a glenoid cavity of a patient'sscapula to identify patient specific anatomy of the glenoid cavity;virtually determining a position of a glenoid component of a reverseshoulder implant assembly using the CT scan so that the glenoidcomponent avoids inserting a screw through the patient's scapula;designing the glenoid template based upon the CT scan of the glenoidcavity and the position of the glenoid component; and fabricating theglenoid template, the glenoid template including an opening to receive aguide, in use, arranged and configured to receive a guide wire, in use,therethrough at a desired location to assist a surgeon during thereverse shoulder implant procedure.
 19. A method for fabricating aglenoid template for a reverse shoulder implant procedure, the methodcomprising: providing software to allow a user to appropriately positiona glenoid component of a reverse shoulder implant assembly; receiving ascan of a glenoid cavity of a patient's scapula including patientspecific anatomy of the glenoid cavity; virtually enabling the glenoidcomponent to be positioned on the scan of the glenoid cavity; andfabricating the glenoid template based upon the positioning of theglenoid component, the glenoid template including an opening to receivea guide, the guide being arranged and configured to receive a guide wiretherethrough so that the guide wire is at a pre-operatively determinedlocation to assist a surgeon during the reverse shoulder implantprocedure.
 20. The method of claim 19, wherein virtually enabling theglenoid component to be positioned on the scan of the glenoid cavitycomprises positioning the glenoid component to avoid inserting a lockingscrew through the patient's scapula.
 21. The method of claim 19, whereinthe scan is a CT (CAT) scan.
 22. The method of claim 19, wherein thescan is an MRI scan.
 23. The method of claim 19, further comprising:mounting the glenoid template onto the glenoid cavity; and inserting theguide wire into the glenoid cavity.
 24. The method of claim 23, furthercomprising using the guide wire to drill a hole in the glenoid cavity toreceive a post of the glenoid component.
 25. The method of claim 23,further comprising inserting at least one instrument over the guide wireto prepare the glenoid cavity for receiving the glenoid component. 26.The method of claim 25, further comprising: removing the glenoidtemplate; removing the instrument and the guide wire; and implanting theglenoid component into the glenoid cavity.
 27. A method for fabricatinga glenoid template for a reverse shoulder implant procedure, the methodcomprising: obtaining a scan of a glenoid cavity of a patient's scapulato identify patient specific anatomy of the glenoid cavity; determininga position of a glenoid component of a reverse shoulder implant assemblybased on the scan; deriving the glenoid template based upon the scan ofthe glenoid cavity and the determined position of the glenoid component;and fabricating the glenoid template, the glenoid template including anopening to receive a guide, the guide being arranged and configured toreceive a guide wire therethrough, the guide wire being at a desiredlocation to assist a surgeon during the reverse shoulder implantprocedure.
 28. The method of claim 27, wherein determining the positionof the glenoid component comprises positioning the glenoid template toavoid inserting a locking screw through the patient's scapula.
 29. Themethod of claim 27, wherein determining the position of the glenoidcomponent is performed virtually on the scan.
 30. The method of claim27, wherein the scan is a CT (CAT) scan.
 31. The method of claim 27,wherein the scan is an MRI scan.
 32. The method of claim 27, whereinderiving the glenoid template comprises aligning a center of the glenoidtemplate with an optical center of the glenoid cavity, the opticalcenter of the glenoid cavity corresponds with an intersection of asuperior-inferior axis and an anterior-posterior axis.
 33. The method ofclaim 27, further comprising: mounting the glenoid template onto theglenoid cavity; inserting the guide wire into the glenoid cavity; andinserting at least one instrument over the guide wire to prepare theglenoid cavity for receiving the glenoid component.
 34. The method ofclaim 33, wherein the at least one instrument is a drill configured todrill a hole in the glenoid cavity to receive a post of the glenoidcomponent.
 35. The method of claim 33, further comprising: removing theglenoid template; removing the instrument and the guide wire; andimplanting the glenoid component into the glenoid cavity.